The disclosure of the following priority application is herein incorporated by reference: Japanese Patent Application No. 2001-119962 filed Apr. 18, 2001.
1. Field of the Invention
The present invention relates to an electronic flash controlling device capable of implementing optimal control on flash light emission quantity.
2. Description of Related Art
Devices that are employed to control the flash light emission quantity in related art include the one disclosed in Japanese Laid-Open Patent Publication No. H 4-182631. This electronic flash controlling device performs a preliminary light emission prior to the main light emission by a flash light emitter when performing a photographing operation with a single lens reflex camera or the like. The preliminary light emission may be achieved by, for instance, repeatedly emitting a small predetermined quantity of light in correspondence to the type of flash light emitter used. In this device, the maximum number of such small light emissions to be performed is set in advance, in order to ensure that a sufficient level of energy is left available for the main light emission after the preliminary light emission is implemented.
However, the flash light emitter is often exchangeable. In the device described above, a single value is set for the maximum number of small light emissions for the preliminary light emission regardless of the type of flash light emitter. For this reason, the onus to be borne during the preliminary light emission is bound to be large if a flash light emitter with a small maximum main light emission quantity for the main light emission is mounted in the camera, which poses problems in that the main light emission becomes disabled and in that a sufficient quantity of light is not emitted during the main light emission.
An object of the present invention is to provide an electronic flash controlling device capable of assuring the required quantity of light to be emitted by a flash light emitter with a small maximum main light emission quantity during the main light emission even after a preliminary light emission.
In order to achieve the object described above, an electronic flash controlling device employed to control a flash light emitting unit that performs a main light emission and a preliminary light emission prior to the main light emission comprises a maximum preliminary light emission quantity setting unit that sets a maximum preliminary light emission quantity for the preliminary light emission during which a smaller quantity of light is emitted than a maximum light emission quantity based upon maximum light emission quantity information regarding a total light emission quantity which the flash light emitting unit is capable of generating; and a preliminary light emission executing unit that engages the flash light emitting unit in the preliminary light emission by using the maximum preliminary light emission quantity set by said maximum preliminary light emission quantity setting unit as an upper limit.
In order to achieve the object described above, an electronic flash controlling system comprises a camera main body having a maximum preliminary light emission quantity setting unit that sets a maximum preliminary light emission quantity for a preliminary light emission during which a smaller quantity of light is emitted than a maximum light emission quantity, based upon maximum light emission quantity information regarding a total light emission quantity which a flash light emitting unit is capable of generating, and a preliminary light emission executing unit that issues an instruction to perform the preliminary light emission to the flash light emitting unit by using the maximum preliminary light emission quantity set by said maximum preliminary light emission quantity setting unit as an upper limit; and an electronic flash device that can be detachably mounted at said camera main body, having said flash light emitting unit that performs a main light emission and the preliminary light emission prior to the main light emission and a preliminary light emission regulating unit that regulates said flash light emitting unit to disallow a preliminary light emission which results in a light emission quantity exceeding a predetermined preliminary light emission quantity even if the instruction has been issued from said camera main body to perform the preliminary light emission which results in the light emission quantity exceeding the predetermined preliminary light emission quantity.